diff --git a/header-only/tests/test_1494-layout-builder.cpp b/header-only/tests/test_1494-layout-builder.cpp
index c9c6201fef..bb813c73e6 100644
--- a/header-only/tests/test_1494-layout-builder.cpp
+++ b/header-only/tests/test_1494-layout-builder.cpp
@@ -58,6 +58,9 @@ using TupleBuilder = awkward::LayoutBuilder::Tuple<BUILDERS...>;
 template <unsigned SIZE, class BUILDER>
 using RegularBuilder = awkward::LayoutBuilder::Regular<SIZE, BUILDER>;
 
+template<class PRIMITIVE, class BUILDER>
+using IndexedBuilder = awkward::LayoutBuilder::Indexed<PRIMITIVE, BUILDER>;
+
 template<class PRIMITIVE, class BUILDER>
 using IndexedOptionBuilder = awkward::LayoutBuilder::IndexedOption<PRIMITIVE, BUILDER>;
 
@@ -1209,6 +1212,62 @@ test_Regular_size0() {
   assert(builder.length() == 0);
 }
 
+void
+test_Indexed() {
+  IndexedBuilder<uint32_t, NumpyBuilder<double>> builder;
+  assert(builder.length() == 0);
+
+  std::cout << "Executing test_Indexed";
+
+  auto& subbuilder = builder.append_index();
+  subbuilder.append(1.1);
+
+  builder.append_index();
+  subbuilder.append(2.2);
+
+  double data[3] = {3.3, 4.4, 5.5};
+
+  builder.extend_index(1);
+  subbuilder.extend(data, 3);
+
+  // [1.1, 2.2, 3.3, 4.4, 5.5]
+
+  std::string error;
+  assert(builder.is_valid(error) == true);
+
+  std::map<std::string, size_t> names_nbytes = {};
+  builder.buffer_nbytes(names_nbytes);
+  assert(names_nbytes.size() == 2);
+
+  auto buffers = empty_buffers(names_nbytes);
+  builder.to_buffers(buffers);
+
+  std::ostringstream out;
+  dump(out,
+       "node0-index", (uint32_t*)buffers["node0-index"], names_nbytes["node0-index"]/sizeof(uint32_t),
+       "node1-data", (double*)buffers["node1-data"], names_nbytes["node1-data"]/sizeof(double));
+
+  std::string check{"node0-index: 0 1 2 3 4 \n"
+                    "node1-data: 1.1 2.2 3.3 4.4 5.5 \n"};
+  assert(out.str().compare(check) == 0);
+
+  assert(builder.form() ==
+  "{ "
+      "\"class\": \"IndexedArray\", "
+      "\"index\": \"u32\", "
+      "\"content\": { "
+          "\"class\": \"NumpyArray\", "
+          "\"primitive\": \"float64\", "
+          "\"form_key\": \"node1\" "
+      "}, "
+      "\"form_key\": \"node0\" "
+  "}");
+
+  clear_buffers(buffers);
+  builder.clear();
+  assert(builder.length() == 0);
+}
+
 void
 test_Indexed_as_IndexedOption() {
   IndexedOptionBuilder<uint32_t, NumpyBuilder<double>> builder;
@@ -1875,6 +1934,7 @@ int main(int /* argc */, char ** /* argv */) {
   test_Regular();
   test_Regular_size0();
   test_Indexed_as_IndexedOption();
+  test_Indexed();
   test_IndexedOption();
   test_IndexedOption_Record();
   test_Unmasked();